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• starting and stopping the ffmpeg video capture within a C ++

  29 août 2015, par yure albuquerque

  It is possible to start FFmpeg from inside a C ++ program and it sending a character ’q’ automatically according to the local time by exemple ?A command line would be to capture the desktop video.

  ffmpeg -f dshow -i video=UScreenCapture output.mp4

  (’q’ to quit)

  I am trying the following code does not work more :

  #include <iostream>
  
  #define WINDOWS_LEAN_AND_MEAN
  
  #include 
  
  #include 
  
  #include <iostream>
  
  #include <thread>
  
  #include <cassert>
  
  #include 
  
  
  
  using namespace std;
  
  
  
  enum { ParentRead, ParentWrite, ChildWrite, ChildRead, NumPipeTypes };
  
  
  
  int main()
  
  {
  
      SECURITY_ATTRIBUTES sa;
  
      sa.nLength = sizeof(sa);
  
      sa.bInheritHandle = TRUE;
  
      sa.lpSecurityDescriptor = NULL;
  
  
  
      HANDLE pipes[NumPipeTypes];
  
      if (!CreatePipe(&amp;pipes[ParentWrite], &amp;pipes[ChildRead], &amp;sa, 0))
  
          return 0;
  
      if (!CreatePipe(&amp;pipes[ParentRead], &amp;pipes[ChildWrite], &amp;sa, 0))
  
          return 0;
  
  
  
      // make sure the handles the parent will use aren't inherited.
  
      SetHandleInformation(pipes[ParentRead], HANDLE_FLAG_INHERIT, 0);
  
      SetHandleInformation(pipes[ParentWrite], HANDLE_FLAG_INHERIT, 0);
  
  
  
      STARTUPINFO si;
  
      ZeroMemory(&amp;si, sizeof(STARTUPINFO));
  
  
  
      si.cb = sizeof(STARTUPINFO);
  
      //si.wShowWindow = SW_SHOW;
  
      si.dwFlags = STARTF_USESHOWWINDOW;
  
      si.dwFlags |= STARTF_USESTDHANDLES;
  
  //    si.dwFlags = STARTF_USEHOTKEY;
  
      si.hStdOutput = pipes[ChildWrite];
  
      si.hStdError = pipes[ChildWrite];
  
      si.hStdInput = pipes[ChildRead];
  
      //si.hStdInput = stdout;
  
      PROCESS_INFORMATION pi;
  
      ZeroMemory(&amp;pi, sizeof(PROCESS_INFORMATION));
  
  
  
      TCHAR cmd[] = "ffmpeg -f dshow -i video=UScreenCapture output.mp4";
  
      if (!CreateProcess(NULL, cmd, NULL, NULL, TRUE, CREATE_NEW_CONSOLE, NULL, NULL, &amp;si, &amp;pi))
  
          return 0;
  
  
  
      CloseHandle(pi.hProcess);
  
      CloseHandle(pi.hThread);
  
  
  
      Sleep(20000);
  
      cout&lt;&lt;"End"&lt;/stop process(failure)
  
  
  
      CloseHandle(pipes[ChildRead]);
  
      CloseHandle(pipes[ChildWrite]);
  
      CloseHandle(pipes[ParentWrite]);
  
      CloseHandle(pipes[ParentRead]);
  
      return 0;
  
  }
  
  </cassert></thread></iostream></iostream>

• Intsallation of ffmpeg-php on Amazon Ec2 Linux AMI

  1er décembre 2015, par Tanny

  I am about two days into attempting to install FFMPEG-php with dependencies on an AWS EC2 instance running the Amazon Linux AMI. I’ve installed FFMPEG, and have read reportedly successful instructions on installing on Red Hat/Fedora. I have followed a number of tutorials and forum articles to do so, but have had no luck yet. As far as I can tell, the main problems are as followed :

  I have installed all the dependency for ffmpeg-php. I run the following command successfully.

  $wget http://downloads.sourceforge.net/project/ffmpeg-php/ffmpeg-php/0.6.0/ffmpeg-php-0.6.0.tbz2
  $tar xvfj ffmpeg-php-0.6.0.tbz2
  $phpize

  But when I run the following command it throw the error like below :

  $sudo ./configure

  configure : error : ffmpeg shared libraries not found. Make sure ffmpeg is compiled as shared libraries using the —enable-shared option}

  I have used enable shared option with shared enable option but it throw the same error.

  On to my question : Has anyone successfully installed FFMPEG-php on Amazon Linux ? Is there a fundamental incompatibility ? If anyone could share specific instructions on installing ffmpeg-php on amazon linux I would be greatly appreciative. Any other insights/experiences would also be appreciated.

• ffmpeg c++/cli wrapper for using in c# . AccessViolationException after call dll function by it's pointer

  25 juillet 2015, par skynet_v

  My target is to write a c++/cli wrap arount ffmpeg library, using by importing ffmpeg functions from dll-modules.
  Later I will use this interface in c#.
  This is my challenge, don’t ask me why))

  So i’ve implemented Wrap class, which is listed below :

  namespace FFMpegWrapLib 
  
  {
  
      public class Wrap
  
      {
  
      private:
  
  
  
      public:
  
          //wstring libavcodecDllName = "avcodec-56.dll";
  
          //wstring libavformatDllName = "avformat-56.dll";
  
          //wstring libswscaleDllName = "swscale-3.dll";
  
          //wstring libavutilDllName = "avutil-54.dll";
  
  
  
          HMODULE libavcodecDLL;
  
          HMODULE libavformatDLL; 
  
          HMODULE libswsscaleDLL;
  
          HMODULE libavutilDLL;
  
  
  
          AVFormatContext     **pFormatCtx = nullptr;
  
          AVCodecContext      *pCodecCtxOrig = nullptr;
  
          AVCodecContext      *pCodecCtx = nullptr;
  
          AVCodec             **pCodec = nullptr;
  
          AVFrame             **pFrame = nullptr;
  
          AVFrame             **pFrameRGB = nullptr;
  
          AVPacket            *packet = nullptr;
  
          int                 *frameFinished;
  
          int                 numBytes;
  
          uint8_t             *buffer = nullptr;
  
          struct SwsContext   *sws_ctx = nullptr;
  
  
  
          void                Init();
  
          void                AVRegisterAll();
  
          void                Release();
  
          bool                SaveFrame(const char *pFileName, AVFrame * frame, int w, int h);
  
          bool                GetStreamInfo();
  
          int                 FindVideoStream();
  
          bool                OpenInput(const char* file);
  
          AVCodec*            FindDecoder();
  
          AVCodecContext*     AllocContext3();
  
          bool                CopyContext();
  
          bool                OpenCodec2();
  
          AVFrame*            AllocFrame();
  
          int                 PictureGetSize();
  
          void*               Alloc(size_t size);
  
          int                 PictureFill(AVPicture *, const uint8_t *, enum AVPixelFormat, int, int);
  
          SwsContext*         GetSwsContext(int, int, enum AVPixelFormat, int, int, enum AVPixelFormat, int, SwsFilter *, SwsFilter *, const double *);
  
          int                 ReadFrame(AVFormatContext *s, AVPacket *pkt);
  
          int                 DecodeVideo2(AVCodecContext *avctx, AVFrame *picture, int *got_picture_ptr, const AVPacket *avpkt);
  
          int                 SwsScale(struct SwsContext *c, const uint8_t *const srcSlice[], const int srcStride[], int srcSliceY, int srcSliceH, uint8_t *const dst[], const int dstStride[]);
  
          void                PacketFree(AVPacket *pkt);
  
          void                BufferFree(void *ptr);
  
          void                FrameFree(AVFrame **frame);
  
          int                 CodecClose(AVCodecContext *);
  
          void                CloseInput(AVFormatContext **);
  
          bool                SeekFrame(AVFormatContext *s, int stream_index, int64_t timestamp, int flags);
  
  
  
          Wrap();
  
          ~Wrap();
  
  
  
          bool                GetVideoFrame(char* str_in_file, char* str_out_img, uint64_t time);
  
      };
  
  
  
      public ref class managedWrap
  
      {
  
      public:
  
  
  
          managedWrap(){}
  
          ~managedWrap(){ delete unmanagedWrap; }
  
  
  
          bool GetVideoFrameToFile(char* str_in_file, char* str_out_img, uint64_t time)
  
          {
  
              return unmanagedWrap->GetVideoFrame(str_in_file, str_out_img, time);
  
          }
  
  
  
          static Wrap* unmanagedWrap = new Wrap();
  
      };
  
  }

  So the imports to libavcodec and etc. are succesful.
  The problem is in AccessViolationException during calling dll func, for example, in OpenInput (i.e. av_open_input in native ffmpeg library)

  The OpenInput func code is below :

  bool FFMpegWrapLib::Wrap::OpenInput(const char* file)
  
  {
  
      typedef int avformat_open_input(AVFormatContext **, const char *, AVInputFormat *, AVDictionary **);
  
  
  
      avformat_open_input* pavformat_open_input = (avformat_open_input *)GetProcAddress(libavformatDLL, "avformat_open_input");
  
      if (pavformat_open_input == nullptr)
  
      {
  
          throw exception("Unable to find avformat_open_input function address in libavformat module");
  
          return false;
  
      }
  
  
  
      //pin_ptr<avformatcontext> pinFormatContext = &amp;(new interior_ptr<avformatcontext>(pCodecCtx));
  
      pFormatCtx = new AVFormatContext*;
  
      //*pFormatCtx = new AVFormatContext;
  
  
  
  
  
      int ret = pavformat_open_input(pFormatCtx, file, NULL, NULL); // here it fails
  
  
  
      return ret == 0;
  
  }
  
  </avformatcontext></avformatcontext>

  So the problem, i think, is that class-fields of Wrap class are in secure memory. And ffmpeg works with native memory, initialising pFormatCtx variable by it’s address.
  Can I avoid this, or it is impossible ?